The present invention relates generally to hybrid transmissions suitable for hybrid electric vehicles (HEVs) equipped with a prime mover such as an internal combustion engine (ICE) and with a motor/generator, and more particularly to a hybrid transmission for a four-wheel drive vehicle, including a differential mechanism connected between a prime mover and a motor/generator for continuously variable speed control.
A Published Japanese Patent Application Publication No. H11(1999)-332019 (hereinafter referred to as “JP11-332019”) shows a four-wheel drive hybrid vehicle. This hybrid vehicle includes a hybrid transmission to receive inputs from an engine and from an electric motor, and to output a driving torque to a first drive axle, and an additional electric motor mounted at a second drive axle, to drive the second drive axle.